Light intensity homogenization system

Abstract

According to the spatial light intensity homogenization system provided by the invention, after parallel light entering the homogenization system sequentially passes through a first fly's-eye lens array, a second fly's-eye lens array, a first lens, a second lens and a third lens, tiny nonuniformity in each thin light beam range after passing through a differential lens group can be compensated for multiple times; according to the invention, light is effectively homogenized, so that required uniform energy can be obtained on an illumination surface, when parallel light changes within an incidence angle range of + / -0.4 degrees, the light intensity unevenness of the illumination surface within a light field range of 0.12 mm * 0.12 mm is lower than 0.2%, the displacement of the light field is smaller than 1 [mu] m, and the uniformity and stability of the light field are ensured.

Description

Technical Field

[0001] The present application relates to the field of optics, and in particular to a light intensity homogenization system. Background Art

[0002] In traditional lighting systems, when the incident angle of spatial light changes, the size, position and uniformity of the uniform light intensity field on the lighting surface will change significantly. The uniformity of light intensity distribution refers to the distribution of light intensity at each point within the lighting range. The better the uniformity, the better the lighting effect. The uniformity of light intensity distribution is directly related to the observation and operation effects of the objects to be observed, affecting the actual work efficiency and work quality. For machine tool lighting, if the light intensity distribution is uneven, it will inevitably lead to problems such as shadows and reflections in the working environment, affecting the work experience and operation effects. Therefore, the uniformity of light distribution of the lighting system is an important indicator for examining the lighting system during actual use.

[0003] Therefore, how to achieve high uniformity of light intensity on a small-sized illumination surface has become a concern for researchers in this technical field. Based on this, it is necessary to design an optical system with a simple structure, high integration, good stability, and the ability to modulate multiple parameters to effectively improve the uniformity and stability of the light intensity on the illumination surface. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a light intensity homogenization system.

[0005] On the one hand, the present application provides a light intensity homogenization system, comprising a differential mirror group and an integrating mirror group arranged along the incident light path direction,

[0006] The micro-mirror group includes a first fly-eye lens array and a second fly-eye lens array;

[0007] The first fly-eye lens array is composed of a plurality of first fly-eye lenses, the surface of the first fly-eye lens facing the light source is a convex surface, the surface facing the illumination surface is a flat surface, and the curvature radius of the convex surface of the first fly-eye lens is 12 to 14 mm;

[0008] The second fly-eye lens array is composed of a plurality of second fly-eye lenses, the surface of the second fly-eye lens facing the light source is a flat surface, and the surface facing the illumination surface is a convex surface; the curvature radius of the convex surface of the second fly-eye lens is the same as the curvature radius of the convex surface of the first fly-eye lens;

[0009] The integrating lens group comprises a first lens, a second lens and a third lens;

[0010] The first lens is a positive-focus aspheric lens, both surfaces of the first lens are convex surfaces, the surface of the first lens facing the light source is an even-order aspheric surface, and the surface of the first lens facing the illumination surface is a standard spherical surface;

[0011] The second lens is a positive-focus aspheric lens, the surface of the second lens facing the light source is a convex surface, and the surface of the second lens facing the illumination surface is a concave surface, the surface of the second lens facing the light source is an even-order aspheric surface, and the surface of the second lens facing the illumination surface is a standard spherical surface;

[0012] The third lens is a positive focus spherical lens, the surface of the third lens facing the light source is convex, the surface of the third lens facing the illumination surface is concave, and the radius of the surface of the third lens facing the light source is smaller than the radius of the surface facing the illumination surface.

[0013] In a possible implementation of the present application, the material of the first fly-eye lens, the second fly-eye lens, the first lens, the second lens, and the third lens is fused quartz.

[0014] In a possible implementation of the present application, the focal lengths of the first fly-eye lens and the second fly-eye lens are the same.

[0015] In a possible implementation of the present application, the focus of the first fly-eye lens coincides with the optical center of the second fly-eye lens.

[0016] In a possible implementation of the present application, the focal lengths of the first fly-eye lens, the second fly-eye lens, the first lens, the second lens, and the third lens are respectively: (Fly-Eye)1 =25~30mm, f (Fly-Eye)2 =25~30mm, f Lens1 =35~40mm, f Lens2 =15~20mm, f Lens3 =40~45mm.

[0017] In a possible implementation of the present application, the first fly-eye lens and the second fly-eye lens are square and have a size of 0.4 mm×0.4 mm.

[0018] In a possible implementation of the present application, the first fly-eye lens array and the second fly-eye lens array are arranged in a 51×51 array.

[0019] In a possible implementation of the present application, the thicknesses of the first fly-eye lens, the second fly-eye lens, the first lens, the second lens, and the third lens are 1 mm to 3 mm, 1 mm to 3 mm, 4 mm to 5 mm, and 2 mm to 3 mm.

[0020] In a possible implementation of the present application, there is a first air gap between the first fly-eye lens array and the second fly-eye lens array, a second air gap between the second fly-eye lens array and the first lens, a third air gap between the first lens and the second lens, a fourth air gap between the second lens and the third lens, and a fifth air gap between the third lens and the illumination surface.

[0021] In a possible implementation of the present application, the thickness of the first air gap, the second air gap, the third air gap, the fourth air gap, and the fifth air gap is d 1 =27~29mm, d 2 =2~4mm,d 3 =2~4mm,d 4 =0~1mm,d 5 =4~5mm.

[0022] In a possible implementation of the present application, the first lens and the second lens are glass aspheric lenses, and the surface shape rotation curve of the aspheric lens satisfies the following equation:

[0023]

[0024] Where c is the curvature of the aspheric lens surface, k is the quadratic curve coefficient of the aspheric lens surface, and a 1 to a 8 is the value of the aspheric polynomial.

[0025] Based on the technical solutions described in any of the above aspects, the technical advantages of this application are:

[0026] 1. After the parallel light of the incident light intensity homogenization system passes through the first fly-eye lens array, the second fly-eye lens array, the first lens, the second lens, and the third lens in sequence, the tiny non-uniformity within the range of each fine light beam after passing through the differential lens group can be compensated multiple times, thereby achieving effective homogenization of the light, so that the required uniform energy can be obtained on the illumination surface.

[0027] 2. When the incident angle of parallel light changes within the range of ±0.4°, the light intensity non-uniformity of the illumination surface within the range of 0.12mm×0.12mm light field is less than 0.2%, and the displacement of the light field is less than 1um, so the uniformity and stability of the light field are guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic diagram of the structure of a spatial light intensity homogenization system provided in one embodiment of the present application;

[0030] Figure 2 A schematic diagram of the structure of a fly-eye lens array provided in one embodiment of the present application;

[0031] Figure 3 A schematic diagram of the structure of a fly-eye lens array provided in one embodiment of the present application;

[0032] Figure 4 A schematic diagram of a system optical path of a spatial light intensity homogenization system provided in one embodiment of the present application;

[0033] Figure 5 A schematic diagram of the uniformity of the light field on the illumination surface of a spatial light intensity homogenization system provided in one embodiment of the present application.

[0034] In the figure: 1-differential mirror group; 11-first fly-eye lens array; 111-first fly-eye lens; 12-second fly-eye lens array; 121-second fly-eye lens; 2-integrating mirror group; 21-first lens; 22-second lens; 23-third lens. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] In the description of this application, it should be noted that the terms "upper", "lower", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0039] It should be noted that, in the absence of conflict, different features in the embodiments of the present application may be combined with each other.

[0040] The specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings.

[0041] See also Figure 1 The present application provides a light intensity homogenization system, comprising a differential mirror group 1 and an integrating mirror group 2 arranged along the incident light path direction,

[0042] The micro-mirror group 1 includes a first fly-eye lens array 11 and a second fly-eye lens array 12;

[0043] The compound eye lens array is also called a micro lens array, which is formed by a series of small lens arrays. The beam homogenization of the compound eye lens is mainly achieved by splitting and redistributing the beam.

[0044] The first fly-eye lens array 11 is composed of a plurality of first fly-eye lenses 111, the surface of the first fly-eye lens 111 facing the light source is a convex surface, the surface facing the illumination surface is a flat surface, and the curvature radius of the convex surface of the first fly-eye lens 111 is 12-14 mm;

[0045] The second fly-eye lens array 12 is composed of a plurality of second fly-eye lenses 121, the surface of the second fly-eye lens 121 facing the light source is a flat surface, and the surface facing the illumination surface is a convex surface; the curvature radius of the convex surface of the second fly-eye lens 121 is the same as the curvature radius of the convex surface of the second lens 22;

[0046] Here, the cross-sectional shapes of the first fly-eye lens array 11 and the second fly-eye lens array 12 can be various, for example, circular, elliptical, rectangular, or square. In this case, the shapes of the first fly-eye lens 111 and the second fly-eye lens 121 are the same as the cross-sectional shapes of the first fly-eye lens array 11 and the second fly-eye lens array 12. Figure 2 , Figure 3 shown. Figure 2 , Figure 3 An example is given of a case where the first fly-eye lens array 11 and the second fly-eye lens array 12 are square and circular respectively. In this case, the first fly-eye lens 111 and the second fly-eye lens 121 are correspondingly square and circular.

[0047] The integrator lens assembly 2 includes a first lens 21, a second lens 22 and a third lens 23;

[0048] The first lens 21 is a positive-focus aspheric lens, both surfaces of the first lens 21 are convex surfaces, the surface of the first lens 21 facing the light source is an even-order aspheric surface, and the surface of the first lens 21 facing the illumination surface is a standard spherical surface;

[0049] The second lens 22 is a positive-focus aspheric lens, the surface of the second lens 22 facing the light source is a convex surface, and the surface facing the illumination surface is a concave surface, the surface of the second lens 22 facing the light source is an even-order aspheric surface, and the surface of the second lens 22 facing the illumination surface is a standard spherical surface;

[0050] The third lens 23 is a positive focus spherical lens, the surface of the third lens 23 facing the light source is convex, the surface of the third lens 23 facing the illumination surface is concave, and the radius of the surface of the third lens 23 facing the light source is smaller than the radius of the surface facing the illumination surface.

[0051] In one embodiment of the present application, the materials of the first fly-eye lens 111, the second fly-eye lens 121, the first lens 21, the second lens 22, and the third lens 23 are fused quartz. Fused quartz has excellent optical properties, and quartz glass has good light transmittance in the entire spectrum from ultraviolet to infrared, and the visible light transmittance is above 92%. When used as a lens material, it has excellent optical properties.

[0052] In one embodiment of the present application, the focal lengths of the first fly-eye lens 111 and the second fly-eye lens 121 are the same, and the two rows of fly-eye lenses with the same focal length can form a symmetrical structure, thereby ensuring that the principal light ray emitted from the second row of fly-eye lenses is parallel to the optical axis, and when the light is incident at a non-0 degree incident angle, it can still overlap on the focal plane of the integrator lens group, so as to improve the uniformity of light intensity in the central area of ​​illumination.

[0053] In one embodiment of the present application, the focus of the first fly-eye lens 111 coincides with the optical center of the second fly-eye lens 121 to improve the overlap of each small light spot after segmentation by the second fly-eye lens, reduce the size of the edge transition zone with uneven light intensity, and further improve the uniformity of light intensity in the central area of ​​illumination.

[0054] In one embodiment of the present application, the focal lengths of the first fly-eye lens 111, the second fly-eye lens 121, the first lens 21, the second lens 22, and the third lens 23 are respectively: (Fly-Eye)1 =25~30mm, f (Fly-Eye)2 =25~30mm, f Lens1 =35~40mm, f Lens2 =15~20mm, f Lens3 =40~45mm.

[0055] In one embodiment of the present application, the first fly-eye lens 111 and the second fly-eye lens 121 are square in shape and have a size of 0.4 mm×0.4 mm.

[0056] In one embodiment of the present application, the first fly-eye lens array 11 and the second fly-eye lens array 12 are arranged in a 51×51 array, that is, the first fly-eye lens array 11 and the second fly-eye lens array 12 are composed of 2601 first fly-eye lenses 111 and 2601 second fly-eye lenses 121.

[0057] In one embodiment of the present application, the lenslet sizes of the first fly-eye lens array 1111 and the second fly-eye lens array 1221 of the present invention, that is, the first fly-eye lens 111 and the second fly-eye lens 121 are both 0.4 mm×0.4 mm, and the arrangement is preferably an odd-numbered symmetrical arrangement of 51 rows×51 columns. This arrangement can ensure that when the incident angle of the parallel light source changes within the range of ±0.4°, the uniformity and position of the light field intensity of the 0.12 mm×0.12 mm illumination surface do not change significantly, and the light field displacement of the uniform light intensity of the illumination surface is less than 1 um.

[0058] In one embodiment of the present application, the thicknesses of the first fly-eye lens 111 , the second fly-eye lens 121 , the first lens 21 , the second lens 22 , and the third lens 23 are 1 mm to 3 mm, 1 mm to 3 mm, 4 mm to 5 mm, and 2 mm to 3 mm.

[0059] In one embodiment of the present application, there is a first air gap between the first fly-eye lens array 11 and the second fly-eye lens array 12, a second air gap between the second fly-eye lens array 12 and the first lens 21, a third air gap between the first lens 21 and the second lens 22, a fourth air gap between the second lens 22 and the third lens 23, and a fifth air gap between the third lens 23 and the illumination surface.

[0060] In one embodiment of the present application, the thickness of the first air gap, the second air gap, the third air gap, the fourth air gap, and the fifth air gap is d 1 =27~29mm, d 2 =2~4mm,d 3 =2~4mm,d 4 =0~1mm,d 5 =4~5mm.

[0061] In one embodiment of the present application, the first lens 21 and the second lens 22 are glass aspheric lenses, and the surface shape rotation curve of the aspheric lens satisfies the following equation:

[0062]

[0063] Where c is the curvature of the aspheric lens surface, k is the quadratic curve coefficient of the aspheric lens surface, and a 1 to a 8 is the value of the aspheric polynomial.

[0064] The expression of c is r is the radius of the surface.

[0065] Exemplarily, the aspheric coefficients of the first lens 21 and the second lens 22 are as follows:

[0066] k <![CDATA[a 2 ]]> <![CDATA[a 3 ]]> <![CDATA[a 4 ]]> <![CDATA[a 5 ]]> First lens 21 0 -3.411E-008 4.194E-007 8.062E-010 -2.261E-011 Second lens 22 0 -2.638E-004 6.501E-006 -2.223E-007 1.003E-009

[0067] The use of a glass aspheric lens structure can effectively improve the parallelism of the light emitted from the integrating lens group 2 in the same field of view, thereby improving the uniformity of the light field intensity of the illumination surface. The light intensity non-uniformity within the 0.12mm×0.12mm light field range is less than 0.2%, achieving high uniformity of the light field intensity of the illumination surface.

[0068] See also Figure 4 , Figure 4In an embodiment, a typical optical path system of a spatial light intensity homogenization system is given. Parallel light is emitted from a light source, and the incident light intensity is homogenized by the system. After passing through the first fly-eye lens array 11, the second fly-eye lens array 12, the first lens 21, the second lens 22, and the third lens 23 in sequence, the light is emitted and converged to the illumination surface. The light intensity homogenization system can compensate for the tiny non-uniformity within the range of each fine light beam after passing through the micro-mirror group 1 for multiple times, thereby achieving effective homogenization of the light, so that the required uniform energy can be obtained on the illumination surface.

[0069] See also Figure 5 , Figure 5 This is a schematic diagram of the uniformity of the light field on the illumination surface of a spatial light intensity homogenization system provided in one embodiment of the present application. The relationship between the transition area, the central area and the light intensity can be seen from the figure.

[0070] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0071] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A light intensity homogenization system, characterized in that: The light intensity homogenization system comprises a differential mirror group and an integrating mirror group arranged along the incident light path direction. The micro-mirror group includes a first fly-eye lens array and a second fly-eye lens array; The first fly-eye lens array is composed of a plurality of first fly-eye lenses, the surface of the first fly-eye lens facing the light source is a convex surface, the surface facing the illumination surface is a flat surface, and the curvature radius of the convex surface of the first fly-eye lens is 12 to 14 mm; The second fly-eye lens array is composed of a plurality of second fly-eye lenses, the surface of the second fly-eye lens facing the light source is a flat surface, and the surface facing the illumination surface is a convex surface; the curvature radius of the convex surface of the second fly-eye lens is the same as the curvature radius of the convex surface of the first fly-eye lens; The integrating lens group comprises a first lens, a second lens and a third lens; The first lens is a positive-focus aspheric lens, both surfaces of the first lens are convex surfaces, the surface of the first lens facing the light source is an even-order aspheric surface, and the surface of the first lens facing the illumination surface is a standard spherical surface; The second lens is a positive-focus aspheric lens, the surface of the second lens facing the light source is a convex surface, and the surface of the second lens facing the illumination surface is a concave surface, the surface of the second lens facing the light source is an even-order aspheric surface, and the surface of the second lens facing the illumination surface is a standard spherical surface; The third lens is a positive focus spherical lens, the surface of the third lens facing the light source is convex, the surface of the third lens facing the illumination surface is concave, and the radius of the surface of the third lens facing the light source is smaller than the radius of the surface facing the illumination surface.

2. The light intensity homogenization system according to claim 1, characterized in that: The materials of the first fly-eye lens, the second fly-eye lens, the first lens, the second lens and the third lens are fused quartz.

3. The light intensity homogenization system according to claim 1, characterized in that: The focal lengths of the first fly-eye lens and the second fly-eye lens are the same.

4. The light intensity homogenization system according to claim 3, characterized in that: The focus of the first fly-eye lens coincides with the optical center of the second fly-eye lens.

5. The light intensity homogenization system according to claim 1, characterized in that: The focal lengths of the first fly-eye lens, the second fly-eye lens, the first lens, the second lens, and the third lens are respectively: (Fly-Eye)1 =25~30mm, f (Fly-Eye)2 =25~30mm, f Lens1 =35~40mm, f Lens2 =15~20mm, f Lens3 =40~45mm.

6. The light intensity homogenization system according to claim 1, characterized in that: The first fly-eye lens array and the second fly-eye lens array are arranged in a 51×51 array.

7. The light intensity homogenization system according to claim 6, characterized in that: The first fly-eye lens and the second fly-eye lens are square in shape and have a size of 0.4 mm×0.4 mm.

8. The light intensity homogenization system according to claim 1, characterized in that: The thicknesses of the first fly-eye lens, the second fly-eye lens, the first lens, the second lens, and the third lens are 1 mm to 3 mm, 1 mm to 3 mm, 4 mm to 5 mm, and 2 mm to 3 mm.

9. The light intensity homogenization system according to claim 1, characterized in that: There is a first air gap between the first fly-eye lens array and the second fly-eye lens array, a second air gap between the second fly-eye lens array and the first lens, a third air gap between the first lens and the second lens, a fourth air gap between the second lens and the third lens, and a fifth air gap between the third lens and the illumination surface.

10. The light intensity homogenization system according to claim 9, characterized in that: The thicknesses of the first air space, the second air space, the third air space, the fourth air space and the fifth air space are d1=27-29 mm, d2=2-4 mm, d3=2-4 mm, d4=0-1 mm and d5=4-5 mm.

11. The light intensity homogenization system according to claim 1, characterized in that: The first lens and the second lens are glass aspheric lenses, and the surface shape rotation curve of the aspheric lens satisfies the following equation: Wherein, c is the curvature of the aspherical lens surface, k is the quadratic curve coefficient of the aspherical lens surface, and a1 to a8 are the values ​​of the aspherical polynomial.

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